The Schiff base LH3 obtained by condensation of 3-formyl-4-hydroxyphenyl-3,4,5-tris(tetradecyloxy)benzoate with 1,3diamino-2-propanol reacts with lanthanide(III) acetate salts to form dinuclear complexes of the type Ln(2)L(2) with the trivalent ions from the first half of the lanthanide series (Ln =Nd, Sm, Gd). These stable and neutral metallomesogens exhibit a rectangular columnar mesophase over a broad temperature range.